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Biomedical subjects

M Bazzucchi

Publications and source records attributed to M Bazzucchi.

11 recordsLinked to original sources
PubMed2006

Modulation of BDNF and TrkB expression in rat hippocampus in response to acute neurotoxicity by diethyldithiocarbamate.

In this study, we examined the expression profile of brain-derived neurotrophic factor (BDNF) and its receptor TrkB in adult rat hippocampus following acute administration of diethyldithiocarbamate (DDTC), a neurotoxic compound which was previously shown to induce microglia activation and cell death. Semiquantitative RT-PCR analysis detected significant variations of BDNF mRNA levels in whole hippocampus homogenates, with a peak at 24h after DDTC injection. Increased BDNF protein expression was demonstrated by immunohistochemistry in various hippocampal subfields. The most relevant increase was observed in the hilus of the dentate gyrus where BDNF levels at 120h were found to be almost four times those of basal levels. Full-length TrkB (TrkB.FL) encoding mRNA was also shown to undergo an earlier increase in the hippocampus of DDTC-treated rats. TrkB immunostaining with an antibody binding both full-length and truncated (TrkB.T) isoforms was found to increase at 120h in the hippocampal CA2 and CA3 regions. These results demonstrate that DDTC modulates the expression of BDNF and its receptor in the adult rat hippocampus and suggest a possible involvement of this neurotrophin in the protective response to DDTC-induced neuronal damage.

Animals↗
PubMed1995

Marginal seal and biocompatibility of a fourth-generation bonding agent.

OBJECTIVES: The pulpal reaction and the marginal sealing of in vivo restored samples using resin composite and Scotchbond Multi-Purpose adhesive system (3M Dental Products) were analyzed in this study. METHODS: Twelve Class I non-exposed cavity preparations were placed on premolars to be removed for orthodontic reasons. They were restored and observed at 7 d and 28 d. RESULTS: The examination of the resin-dentin interface under the scanning electron microscope (SEM) revealed: 1) a gap-free attachment between adhesive resin and dentinal surface in 80% of the areas studied, 2) penetration of resin tags into the dentinal tubules, and 3) formation of a 3-5 micrometer thick acid-resistant hybrid layer. Microfissures measuring about 10 micrometers were observed in only 20a% of the areas studied; these were located along the walls of the cavities, especially near the enamel in zones where there was a lower concentration of dentinal tubules. The histological analysis, carried out 7 d after preparation of the restoration, did not show any alteration of the pulp. After 4 wk, reparative dentin was produced in the pulpal areas corresponding to the restored cavities. SIGNIFICANCE: The quantity of newly formed dentin is correlated with the distance from the cavity to the pulp. The results indicate that acid-etching of vital dentin using 10% maleic acid does not impair pulpal healing in deep Class I cavities and that the Scotchbond Multi-Purpose adhesive system is able to preserve the morphological and biological integrity of the pulpo-dentinal complex.

Acid Etching, Dental↗
PubMed1994

In vivo and in vitro analysis of a bonding agent.

Recently many researchers have become interested in the adhesion of composite resin to the dentinal surface. Because it is easier to obtain good composite resin adhesion when a surface is free from smear plug, several chemical agents (acids or linking agents) have been suggested for surface preparation. Nevertheless, the pretreatment of dentin leads to an increase of pulpal outflow, which can interfere with the bonding agent's adhesion. Thus, new-generation dentinal bonding agents appeared on the market. They use a pool of highly absorbent primers to facilitate the scattering of the agent in the dentin substratum under humid conditions. The present study shows the results, obtained with the help of scanning electron microscopy, of resinous penetration into the tubular structures of dentin using a latest-generation bonding system. The in vivo and in vitro tests showed a deep scattering of intermediate fluid resin into tubules, even in the presence of physiologic outflow of dentinal fluids.

Acid Etching, Dental↗
PubMed1993

[An ultrastructural analysis of the peritubular dentin and of the tubular lumen in healthy teeth].

In this study the authors examined some specimens of fractured dentine of embedded healthy teeth, of people aged between 20 and 30. Connecting the scanning electron microscopy to a system of computerised analysis of spectrometry (EDS) allowed the analysis of the qualitative composition of the specimens. Therefore, the authors described the tubular structure of the sound, the peri- and the intertubular dentine, the winding course of the dentinal tubules and in some specimens, the presence of cylindrical structures inside the tubules. The EDS analysis demonstrated that these tubular structures have the same composition as the intertubular dentine. Former studies described hollow cylindrical structures having a similar morphology solely as a response of the odontoblasts to white spots. On the contrary, in this study it was demonstrated that it is possible to find cylindrical structures which are definitely mineralized in sound teeth without caries. However, the presence of such formations is not concomitant with the disappearance of peritubular dentine which is a typical structural modification of the pathological advancement of the carious lesion.

Adult↗
PubMed1990

[Reduced cavities for amalgam fillings].

Teeth with small interproximal lesions can be treated with reduced cavities for amalgam. This kind of reconstruction produces a good retention while removing less healthy dental tissue and safeguarding the aesthetic appearance with the advantages of amalgam, which is better compared with composite resins, especially for proximal contact and marginal adaptation.

Dental Amalgam↗
PubMed1984

[Tetanus prevention in a hospital emergency department].

Antibody titers to tetanus toxin in a group of 304 patients were estimated by means of the passive haemagglutination with turkey erythrocyte test. It appears that some sorts of workers, particularly the female subjects, do not get vaccinated against tetanus, although vaccination is provided for by law. Furthermore, it has been demonstrated that about 17% of the regularly vaccinated subjects are non protected and that antibody titers keep on protection levels in a high percentage of subjects even at a distance of ten years.

Adolescent↗
PubMedDate not supplied

[An ultrastructural analysis of dentin treated with chemical agents].

Dental last generation bonding systems require the total removal of smear layer and smear plug by chemical solutions. Intermediate fluid resin can penetrate the dentinal tubes obtaining a better anchorage to the dental structures. The department of Operative dentistry of the University of Rome "La Sapienza" has carried research observing by means of the SEM the ultrastructural aspect of smear layer and the effect of dentin treatment with five different chemical agents.

Acrylic Resins↗
PubMedDate not supplied

Dentinal adhesive with composite restorations: a clinical and microstructural evaluation.

It is generally accepted that the application of dentin-enamel adhesive should involve not only the etched enamel but also the dentinal surface. For this purpose, new bonding agents requiring dentin etching and the combined use of bifunctional groups (Primers) as well as hydrophilic resins have been introduced. This study used scanning electron microscopy to analyze the relationship between dentin and fluid resin of three bonding agents. The results demonstrated that the adhesive monomers easily penetrated the etched dentin, sealing the dentinal tubules and creating a resin dentin interdiffusion zone (hybrid layer). As a result, the microleakage between dentin and resin composite restorations, responsible for postoperative tooth sensitivity, pulpal inflammatory reaction, and secondary decay, is greatly reduced.

Acid Etching, Dental↗